Hi if you want to windsurfing in Turkey you can find a lot of places
like Marmara erelisi, Alaçat1, Gökçeada, 0stanbul.

Here is the a web side about surfing in Turkey. www.windsurftr.com
This is turkish but you can use google translate to understand.
Also you can ask your question to responsible person via info@windsurftr.com